South Africa's status as the top-ranked Test-playing nation has been dented after their crushing defeat in India last month and is in danger of being eroded completely by England over the next month or two.
The two nations begin a four-match Test series in Durban on Saturday, which is expected to be evenly matched and should provide answers to several questions asked of both amid their recent trials.
England will look to solve personnel problems in key batting and bowling slots and build more consistency in their selections, while South Africa seek to dispel suggestions that they are a side on the decline, suddenly lacking in the confidence that has been the hallmark of their reign as the world's top Test side.
Both countries return to seam-friendly wickets after losing on spinning tops in India and -- for some of the time -- the United Arab Emirates in the last two months.
South Africa's limitations against spin were cruelly exposed in India in a one-sided four-test series, which the home team won 3-0 and which could have been a whitewash had weather not intervened.
England were beaten 2-0 by Pakistan in a three-match series in the UAE, prompting several changes -- notably the axing of stalwart Ian Bell -- to the squad for the South African tour.
England are still seeking to solve the longstanding problem of finding a reliable opening partner for Alastair Cook, having gone through seven in 39 Tests since Andrew Strauss retired in 2012.
Alex Hales will be the eighth to open the innings with the captain while the No.3 slot is likely to go to Nick Compton, making a return to the side after lasting only nine Tests at the top of the order after being appointed Strauss's immediate successor.
It will be a boost to England's confidence that each of their scheduled top six batsmen go into the series with a score of 50 or more under their belts from the two warm-up matches over the last week.
They included centuries from Cook and Joe Root, who is looking to take his Ashes form from earlier this year into the series.
"We will have to play some strong cricket, be disciplined and play at our best if we are going to compete with them," Root said this week.
But South Africa have lost much of their swagger since charismatic captain Graeme Smith and all-rounder Jacques Kallis retired.
After their poor batting display in India, they have persuaded a reluctant AB de Villiers to again don the wicketkeeper's gloves to make room for an extra batsmen.
But they have received a boost with attack bowler Dale Steyn passing a fitness test after a groin injury provided him with a much-needed break and a chance to rekindle the hunger of old. He could yet provided a talismanic influence.
The Boxing Day Test will be followed by a New Year's Test in Cape Town from Jan. 2-6. The third and fourth matches will be played in the high altitude of Johannesburg and Pretoria next month.
